Why Is My Epson L1800 DTF Printer Printing Yellow and Black Incorrectly? Troubleshooting Ink Channel Misrouting and Color Overlap

Question:

My Epson L1800 DTF printer prints with yellow and black colors, resulting in shadowing or appearing before the actual image. Sometimes, yellow and black print over the white layer. During the nozzle check, the yellow and black components have swapped positions and now face opposite directions. Additionally, the black text appears yellow. What could be causing this problem?

Answer:

Here at BCH Technologies, we’re genuinely grateful for your continued support—especially on our YouTube channel (https://youtube.com/@bchtechnologies). Your questions and feedback play a vital role in refining our technical know-how and helping others troubleshoot similar issues.

Now, let’s get into the problem.

Based on your description, this issue points strongly to ink channel misrouting, where the yellow and black ink lines are connected to the wrong ports on the printhead or were swapped at the dampers or ink tank connections. It’s a relatively common problem, especially in modified printers like DTF setups, where the ink flow system has been altered or extended.

Here's what’s likely happening:

• Incorrect ink tube connection: The yellow line is going to the black channel and vice versa. That’s why your nozzle check is showing yellow firing where black should be, and black where yellow should be.

• Color misplacement: Because the printer confuses yellow with black and black with yellow, it prints the wrong color in some regions of the image. This leads to the unusual behavior you're seeing—yellow appearing as text when it should be black, and colors layering in the wrong order, such as yellow or black being overlaid on top of white.

• Reversed nozzles: You mentioned that the yellow and black are facing in opposite directions on the nozzle check. That’s a strong sign that the printer's firmware is firing the wrong nozzle for the intended ink—another confirmation of swapped ink routing.

How to Fix It:

1. Trace the ink lines from your tanks to the printhead:

   • Follow each color tube and ensure it connects to the corresponding damper and printhead port.

   • Use the Epson L1800 color channel order for reference: usually C, M, Y, K, LC, LM (left to right or proper to left depending on your setup). You can look up a diagram for the exact order.

2. Check the dampers:

   • Make sure they are inserted into the correct ports and not accidentally switched. Yellow and black are typically far apart in Epson models, so if they’re next to each other now, that’s a red flag.

3. Reconnect the ink tubes properly:

   • If you discover that yellow and black were swapped, disconnect them and reattach each one to its correct position.

4. Run a cleaning cycle:

   • After fixing the routing, run at least one to two cleaning cycles using the printer's software utility.

5. Do a nozzle check:

   • The goal is to ensure each color fires from the correct channel. If yellow and black now appear in the right spots and directions, you’ve resolved the issue.

This situation is quite common in DTF printers that have undergone conversions, so you’re not alone—and your careful observation of nozzle check patterns is a big help in identifying the problem. You’re close to fixing it, and with the ink lines properly routed, your printer should return to normal behavior.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. Therefore, we're unable to provide remote troubleshooting, suggestions, or support for printer repairs. We offer an in-person evaluation and repair service via our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Given the high demand, we operate on a first-come, first-served basis. It might take a few weeks before we can get to your printer after drop-off. Our services can cover full printer repairs or specific part replacements, depending on your needs. That said, we understand our repair pricing might not be the most affordable. Therefore, we recommend starting with DIY solutions through online research. One great resource is our YouTube channel homepage (https://youtube.com/@bchtechnologies). Use the search icon next to the “About” tab to locate videos on similar issues. Since we’ve published videos for nine years, this is the quickest way to find helpful content, including from other creators.

Thank you again for your question, your support, and for being a part of our community. Keep up the great work, and we hope your L1800 is back to producing crisp, vibrant prints soon!